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Tuan PM

Dong Viet Co.Ltd

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Github Repository: https://github.com/tuanpmt/esp_mqtt

ESP8266 is a solution for internet connection via wifi with great price, and it will become more common for IOT applications where system libraries serve these applications become more complete and stable.

This is MQTT client library for ESP8266, port from: MQTT client library for Contiki (thanks)


  • Support subscribing, publishing, authentication, will messages, keep alive pings and all 3 QoS levels (it should be a fully functional client).
  • Support multiple connection (to multiple hosts).
  • Support SSL connection
  • Easy to setup and use



  • Copy file include/user_config.sample.h to include/user_config.local.h and change settings, included: SSID, PASS, MQTT configurations ...

Make sure to add PYTHON PATH and compile PATH to Eclipse environment variable if using Eclipse

git clone --recursive https://github.com/tuanpmt/esp_mqtt
cd esp_mqtt
make clean
make SDK_BASE=/tools/esp8266/sdk/ESP8266_NONOS_SDK ESPTOOL=tools/esp8266/esptool/esptool.py all
make ESPPORT=/dev/ttyUSB0 flash


See file: user/user_main.c

Publish message and Subscribe

/* TRUE if success */
BOOL MQTT_Subscribe(MQTT_Client *client, char* topic, uint8_t qos);

BOOL MQTT_Publish(MQTT_Client *client, const char* topic, const char* data, int data_length, int qos, int retain);

Already support LWT: (Last Will and Testament)

/* Broker will publish a message with qos = 0, retain = 0, data = "offline" to topic "/lwt" if client don't send keepalive packet */
MQTT_InitLWT(&mqttClient, "/lwt", "offline", 0, 0);

Default configuration

See: include/user_config.sample.h

Define protocol name in include/user_config.local.h

#define PROTOCOL_NAMEv31  /*MQTT version 3.1 compatible with Mosquitto v0.15*/
//PROTOCOL_NAMEv311     /*MQTT version 3.11 compatible with https://eclipse.org/paho/clients/testing/*/

Create SSL Self sign

openssl req -x509 -newkey rsa:1024 -keyout key.pem -out cert.pem -days XXX

SSL Mqtt broker for test

var mosca = require('mosca')
var SECURE_KEY = __dirname + '/key.pem';
var SECURE_CERT = __dirname + '/cert.pem';
var ascoltatore = {
  //using ascoltatore
  type: 'mongo',
  url: 'mongodb://localhost:27017/mqtt',
  pubsubCollection: 'ascoltatori',
  mongo: {}

var moscaSettings = {
  port: 1880,
  stats: false,
  backend: ascoltatore,
  persistence: {
    factory: mosca.persistence.Mongo,
    url: 'mongodb://localhost:27017/mqtt'
  secure : {
    keyPath: SECURE_KEY,
    certPath: SECURE_CERT,
    port: 1883

var server = new mosca.Server(moscaSettings);
server.on('ready', setup);

server.on('clientConnected', function(client) {
    console.log('client connected', client.id);

// fired when a message is received
server.on('published', function(packet, client) {
  console.log('Published', packet.payload);

// fired when the mqtt server is ready
function setup() {
  console.log('Mosca server is up and running')

Example projects using esp_mqtt:

MQTT Broker for test

MQTT Client for test